Rootstock Fusion : Grafting Cannabis for Stronger Crops

CANNABIS CULTURE – Grafting is a process by which two crops are fused collectively, to make a single, two-part plant. The half under the graft union, together with the roots and decrease stem, is called the rootstock. The prime a part of the plant, above the graft union, which bears leaves and fruit, is called the scion.

History and Applications

Grafting has been utilized in woody crops like pears and grapes since at the least 500 B.C.E. References to grafting seem in Chinese and Greek texts from the fifth and fourth centuries B.C.E., respectively, and point out that the apply turned prevalent centuries earlier. In the previous few many years, vegetable growers additionally started grafting for numerous advantages. Cannabis too, might be grafted fairly simply, and there are lots of attainable purposes.

In the yr 2000, growers in Japan and Korea grew 700 million grafted greens. Vegetables, and different crops resembling fruit timber and ornamentals, can profit from rootstocks which are immune to pests and pathogens. Breeders develop rootstocks immune to illnesses like root rot, infestations of root-knot nematodes, and even to assault from bugs akin to Phylloxera (which are sometimes incorrectly known as ‘root aphids’, though they’re intently associated). In reality, the grape business in Europe was devastated by an infestation of Phylloxera, introduced over from North America across the yr 1860. European vinifera grapes had no native publicity to the pest, and subsequently have little resistance to it. To mitigate the issue, growers started utilizing rootstocks from North American grape species comparable to Vitis lubrusca, with native resistance to Phylloxera. The American rootstocks have been a profitable answer. Cannabis might additionally profit from the breeding and improvement of rootstocks immune to pests and illnesses. For instance, as legal guidelines loosen, and hashish growers transfer to outside area manufacturing, root-knot nematodes will develop into a administration problem. Techniques like soil solarization can scale back pest nematode populations, however eradication could also be very troublesome to realize. Resistant or tolerant hashish rootstocks might subsequently be very useful.

Grafting can be utilized to mix the favorable root system of 1 plant, which can in any other case have poor attributes, with the favorable foliage, flowering, or fruiting of one other plant, which could usually have a weak root system. Using this technique, grafting hashish might improve vigor and yield, on account of combining favorable traits, whereas circumventing unfavorable ones. Tomato growers have reported elevated yields, when rising heirloom varieties grafted onto superior rootstocks.

Like cloning, grafting is an asexual propagation method; subsequently, grafting can be utilized to supply the identical degree of crop uniformity as cloning. Rootstocks themselves could be clones, or they are often seedlings. Combining a seedling rootstock, with a clone scion, is a way utilized in species that don’t have robust rooting as clones, similar to some conifer species. Conifer growers germinate seeds, and as soon as the seedlings have giant sufficient stems, they graft scions of the specified clone onto the seedlings. From then on, the seedlings act solely as rootstocks. Any shoots which may sprout from a rootstock are thought-about suckers and are pruned away. Suckers may be deterred by shading the stem with a corrugated wrap (which is black on inside to dam mild, and white on the surface to mirror it), till the plant develops a shady cover and woody stem. At that time, suckers can be much less more likely to sprout.

Citrus timber are typically grafted onto clonal rootstocks, and typically onto seedling rootstocks. Lemons for instance, are sometimes grafted onto clonal rootstocks, and should blow over in robust winds, on account of missing a taproot, and being grown in sandy soil. Clones and clonal rootstocks have a sprawling root system, and not using a robust, central taproot, and subsequently are much less secure than seedlings. Grapefruit, in distinction to lemon, is usually grafted onto seedling rootstocks, which have very deep taproots. The taproots penetrate into deep clay layers that present stability, and a constant provide of moisture. Grafting Cannabis onto seedling rootstocks may create extra secure crops, for progress in deep natural soils, or sandy soils, particularly the place excessive winds are possible. For instance, the windy circumstances, and deep natural soil of the Great Plains of North America, might be problematic for plant stability. Not solely do seedlings have a deep, robust, central taproot, additionally they put out what are generally known as anchor roots (Figure X). Anchor roots develop laterally from the stem close to the soil line, and have excessive tensile power, for stabilizing crops in excessive winds.

Another profit, which hashish crops might achieve from the deeper root system of a seedling rootstock, is elevated water uptake, when grown in drought or probably water-stressed circumstances. The much less water stress a plant experiences, the extra it photosynthesizes and grows. Deep layers of soil keep moist far more persistently than the floor, so entry to this moisture by way of a taproot is useful.

How to Graft Cannabis

There are a number of totally different methods that can be utilized to graft hashish, similar to splice grafting, saddle grafting, strategy grafting, and cleft grafting. I’ve discovered that cleft grafting is straightforward and really profitable (almost 100% success price) when grafting hashish, in order that’s the method I’ll clarify on this article. Conveniently, grafting may be achieved concurrently together with rooting of a clonal rootstock; combining these two processes can prevent time. Alternatively, if in case you have established seedlings or rooted clones, they can be utilized as rootstocks, however might want to slot in a humidity dome, or be stored in a bigger high-humidity surroundings, till the graft union is established. Note that the grafting process also needs to happen in a shady, cool, humid location, to stop water loss from the cuttings.



  • To begin, you’ll want vegetable grafting clips, which can be found on-line, for numerous stem sizes. You may also use parafilm grafting tape to wrap the graft union, however I recommend utilizing the clips. The ease and velocity of utilizing the clips will lower labor, and improve the speed of profitable grafts, by permitting you to maneuver the grafted crops right into a humidity dome sooner, and thereby keep away from water loss.
  • A tall humidity dome (the type which are near 30 cm tall are greatest).
  • A warmth mat for propagation, ideally with a temperature controller, set at 25.5 levels C (78 levels F).
  • Rooted or unrooted clones, or 13-18 cm tall seedlings with Four-5 nodes, to make use of as rootstocks
  • Small rockwool cubes or different rooting medium, if utilizing unrooted clones as rootstocks
  • Fresh cuttings of the specified pressure, to make use of as scions. The stem diameter of those scions have to be almost the identical diameter because the rootstock stems. Each slicing ought to embrace the tip of a shoot, in addition to leaves and axillary buds or shoots.
  • A light nutrient answer with an EC round zero.Four mS/cm, and a pH round 5.6 (if utilizing rockwool). If utilizing different media, maintain the pH nearer to



  • If utilizing an unrooted clone because the rootstock: Cut a shoot from a mom plant, about 15 centimeters lengthy, such as you would for a traditional clone. The base of the shoot ought to have a semi-woody stem. Lightly wound the edges of the stem close to the bottom, utilizing scissors in a mild scraping motion. Only wound the part that might be under the floor of the rooting medium. Stick the clone in a nutrient-soaked rockwool dice, as you usually would for rooting. I want to keep away from utilizing rooting hormones, because it’s pointless for hashish, and will have potential well being implications. Ignore this step in case you are beginning with a rooted clone or seedling.
  • Prepare your unrooted clone, rooted clone, or seedling, to be a rootstock, by chopping the stem parallel to the bottom (a horizontal reduce), thereby eradicating the highest of the plant, and leaving solely a stem. Preferably, the remaining stem ought to be at the least 5 centimeters tall, to maintain the graft union away from the floor of the soil or different medium. This will assist forestall illnesses, by retaining the graft union clear. If you’re utilizing a seedling as a rootstock, reduce the stem slightly below the cotyledons.
  • Use the razor, to rigorously cut up the stem of the rootstock, down the very middle of the floor of the primary minimize. The cut up should stay centered because it goes down, or the stem won’t be robust sufficient. Cut down about 1.5 centimeters.
  • Prepare the scion, beginning with a recent chopping of the specified pressure. Point the bottom of the chopping in the direction of you, and punctiliously reduce the bottom right into a wedge form, utilizing two clear attracts of the razor. The angle of the wedge ought to be as slender as attainable, and it ought to be about 1.5 cm lengthy, as to suit into the cleft rootstock. Cut the very tip of the wedge to make it flat, in order that it settles into the rootstock with good contact.
  • Gently push the wedge of the scion into the cleft rootstock, then use the grafting clip to safe the connection. The clip ought to be positioned as to squeeze the cleft stem closed across the wedge of the scion. The two related stems might not have the very same diameter; to compensate, push the wedge of the scion to at least one aspect of the rootstock in order that it aligns evenly with no less than one aspect. This will permit a vascular connection to type between the 2 crops, within the cambial layer.
  • Trim the ideas of the leaves of the scion, to scale back transpirational water loss. Don’t take away greater than half of every leaflet (finger). Some leaf materials is required for saved carbohydrates and hormones utilized in rooting, and for photosynthesis as soon as the brand new plant is established.
  • Place the newly grafted plant within the humidity dome, on the warmth mat, and maintain it in a heat, shady or reasonably illuminated space, for about 7 days, or till you detect new progress. During this time, water rigorously, to keep away from overwatering and ‘drowning’ the scion.
  • Begin acclimating the plant to regular rising circumstances, by steadily growing the lighting depth, and progressively decreasing the humidity degree. If you began with an unrooted clone as your rootstock, wait no less than till you discover roots rising from the underside of the medium, to start the acclimation course of.



Following these steps, you’ll discover that grafting hashish is a simple course of. You may even need to attempt different methods, resembling strategy grafting, when you’re acquainted with cleft grafting.

Virus Indexing

In 1898 Martinus Beijerinck coined the time period ‘virus,’ when he described Tobacco Mosaic Virus, the primary virus ever found. Plant viruses trigger signs together with contorted foliage, necrotic spots, and mosaic yellowing. One novel use for grafting is testing for plant viruses— a follow often known as virus indexing. If you believe you studied that a plant is contaminated with a virus, however haven’t any different method of testing it to make a willpower, you’ll be able to graft a scion from a wholesome plant onto it. If the scion grows out displaying the virus-like signs noticed within the rootstock, it signifies the presence of a virus. When virus indexing, take away one department of the plant suspected to have the virus, and graft on a wholesome scion. Protect the scion from vibrant mild and dry air, till the graft union is established.

Multi-Strain Plants for Legal Compliance

One ultimate, fascinating software of grafting hashish, is creating crops that produce multiple pressure. In places the place the variety of crops you’ll be able to legally develop is restricted, scions of a number of strains might be grafted onto a single plant, to offer selection, with out growing the plant rely. Each department of a plant might have a unique pressure grafted onto it. A grafted, multi-strain plant could possibly be flowered to complete its life-cycle, and produce a mess of various buds, or might be used as a mom plant, to supply clones of a number of totally different strains. Check together with your native authorities to confirm authorized compliance.


Grafting has many compelling makes use of, and will play a serious position in the way forward for the hashish business. Imparting pest and illness resistance, growing yields, offering stability in excessive winds, enhancing drought tolerance, virus indexing, and rising a number of strains per plant, are all ways in which grafting might be utilized to hashish manufacturing.  



Joe Bender is an skilled grower and the driving drive behind Cannabis Crop Solutions LLC



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